Add test_load_from_config_prefix_stripping-t to test groups

Adds the new prefix stripping validation test to the default-g4 test group
along with mysql-auto_increment_delay_multiplex=0-g4, mysql-multiplexing=false-g4,
mysql-query_digests=0-g4, and mysql-query_digests_keep_comment=1-g4 groups.

This ensures the test is run as part of the regular test suite.

test/tap/groups/groups.json

@@ -217,6 +217,7 @@
   "eof_packet_mixed_queries-t" : [ "default-g4","mysql-auto_increment_delay_multiplex=0-g4","mysql-multiplexing=false-g4","mysql-query_digests=0-g4","mysql-query_digests_keep_comment=1-g4" ],
   "ok_packet_mixed_queries-t" : [ "default-g4","mysql-auto_increment_delay_multiplex=0-g4","mysql-multiplexing=false-g4","mysql-query_digests=0-g4","mysql-query_digests_keep_comment=1-g4" ],
   "test_load_from_config_validation-t" : [ "default-g4","mysql-auto_increment_delay_multiplex=0-g4","mysql-multiplexing=false-g4","mysql-query_digests=0-g4","mysql-query_digests_keep_comment=1-g4" ],
+  "test_load_from_config_prefix_stripping-t" : [ "default-g4","mysql-auto_increment_delay_multiplex=0-g4","mysql-multiplexing=false-g4","mysql-query_digests=0-g4","mysql-query_digests_keep_comment=1-g4" ],
   "mysql-show_ssl_version-t": [ "default-g4", "mysql-auto_increment_delay_multiplex=0-g4", "mysql-multiplexing=false-g4", "mysql-query_digests=0-g4", "mysql-query_digests_keep_comment=1-g4" ],
   "mysql-watchdog_test-t": [ "default-g4", "mysql-auto_increment_delay_multiplex=0-g4", "mysql-multiplexing=false-g4", "mysql-query_digests=0-g4", "mysql-query_digests_keep_comment=1-g4" ],
   "pgsql-extended_query_protocol_query_rules_test-t": [ "default-g4", "mysql-auto_increment_delay_multiplex=0-g4", "mysql-multiplexing=false-g4", "mysql-query_digests=0-g4", "mysql-query_digests_keep_comment=1-g4" ],